The sessions were organized by Kevin Freistat, a Florida autograph dealer, according to ESPN.

The two sessions reported Monday are in addition to four sessions that were uncovered last week. ESPN reported the six signings occurred in three states, for three brokers, in less than a month. According to ESPN's sources, Manziel signed his name more than 4,400 times.

Freistat, Manziel and Texas A&M declined to comment to ESPN. Manziel's lawyer said last week that his client had signed hundreds of autographs in the past year, but he had no knowledge of whether Manziel was paid for them.

The uniformity of Manziel's signatures has one dealer believing that Manziel isn't signing randomly.

"With college guys, you'll often see different color pens, varying penmanship, autographs signed in different places on a photo," Sean Morgan, who owns a sports marketing and memorabilia company called Famous Ink, told ESPN. Morgan said his company doesn't buy or sell autographs of current college players. "With Johnny, it's all the same."

Manziel is being investigated by the NCAA for the signings. If it is proved that he was paid for his autograph, his eligibility will be very much in question.